A European bid to clamp down on the $100bn-a-year global trade in illegal timber has been poorly designed, badly managed and largely ineffective, according to a damning report by the EU’s court of auditors.

But 12 years after launching an action plan to end the trade, results from the EU’s €300m aid programme to 35 partner countries have been “meagre” according to the auditors’ report, with problems at the demand and supply ends of the trade chain.

Four EU countries - Greece, Spain, Hungary and Romania - have still not implemented an EU timber regulation proposed five years ago, allowing an easy passage to market for the fruits of deforestation.

“As the chain of control is only as strong as its weakest link in the single market, illegal timber could still be imported into the EU via these four countries,” Karel Pinxten, one of the auditors of the report, said. “The EU should put its house in order.”

Interpol estimates that illegal logging is responsible for up to 30% of all global forestry production. Penalties for wood trafficking across the EU vary though, from €7,500 in Bulgaria to €5m in the Czech Republic and an unlimited sum in the UK.

On the supply side, part of the problem rests with a poor prioritisation of aid, the auditors say. Liberia received €11.9m to tackle illegal logging, when its yearly wood exports to the EU only averaged €5m.

The commission says the funding was needed as illegal logging has been used to fund Liberian militias. The Central African Republic similarly received €6.8m, when it exported just €18m of timber to the EU.

“If you compare these amounts there is something surreal about it,” Pinxten said. “The imbalance between the amounts spent and imported from these countries is amazing.”

Despite the sums of money involved, the commission did not develop criteria to assess the scale of illegal logging in partner countries, their commitment and potential to act, or their trade importance.

Poor monitoring, licencing and delivery procedures led to the failure of a number of projects, including a €2.27m timber tracking system in Cameroon.

A European commission reply in the report says: “The commission recognises the need to develop more specific objectives, milestones and a common roadmap as well as the need to more systematically monitor ... implementation. The recommendations of the ongoing evaluation will certainly help in this effort.”